PageRank is Google’s primary method of ranking web pages in their index. PageRank refers to a hidden value (presumably between 1 and 10) that ranks a page based on importance.

Web pages with higher PageRank (PR for short) are thought (by Google) to be more important, and thus get ranked higher than pages with lower PR.

When one web page links to another web page, they give that page some of their PageRank. This concept is what gives PageRank its power. The theory behind it is this: Let’s say a large, popular website (let’s say CNN.com) links to your web page. The page on their site would likely have a high PR. Google looks at this link to you and gives you a higher PR because they trust CNN.com.

When Google indexes your website, they search for links to your pages, which are called backlinks. The number and quality of backlinks to your website’s pages have a major impact on your PageRank.

Simply put, the more quality links you can get to your website, the higher your website will rank in Google Search.

According to Google, PageRank is:

PageRank reflects our view of the importance of web pages by considering more than 500 million variables and 2 billion terms. Pages that we believe are important pages receive a higher PageRank and are more likely to appear at the top of the search results.
PageRank also considers the importance of each page that casts a vote, as votes from some pages are considered to have greater value, thus giving the linked page greater value. We have always taken a pragmatic approach to help improve search quality and create useful products, and our technology uses the collective intelligence of the web to determine a page’s importance.